The term communication services is meant to mean conventional telephony services, telex services, datapack services, datel services, telefax services, videotext services, ISDN-services, mobile telephony services, personal paging services, tele-point-services and general communication between two or more parties. The services recited above are only examples of the services possible and are not intended to limit the scope of the invention.
The term telecommunication network is normally meant to mean the telephone networks, telex networks, circuit connected data networks, picture information transfer networks, private telecommunication networks, radio networks, satellite communication networks and general carriers of the communication services, such as analog transmission, digital transmission, synchronous, multiplex or asynchronous multiplex transmission, ATM, etc., for example. These networks are recited solely by way of example and the invention is not restricted thereto.
The term functionality is meant to mean the ability to perform an operation in a telecommunication network. Examples of functionality include activities and services that can be performed in the telecommunication network. Examples of functionalities include an enquiry to establish a connection path or route between two parties, digit analysis, billing or ticketing. Although not necessary, the functionality may require the availability of dedicated equipment for carrying out the functionality. For instance, if the functionality is to receive tones and to analyze tones, it is necessary to make a tone receiver accessible. Other examples of functionalities include voice-controlled speech information, number translation service, conference calls. Other examples of functionality include the functionalities described in the aforesaid five Swedish patent applications, namely communication in the form of a meeting, personal paging, a method of establishing cooperation with a functionality, meeting connection establishment and communication via intermediaries. Still another example of functionality is the ability of being able to choose from among several alternatives.
The term connection is meant to mean a circuit-coupled connection or a package-coupled connection. The term to establish a connection is meant to mean in the circuit coupled case that a circuit-coupled connection is established between two hardware terminal devices (or equipment) and in the package coupled case it is meant that a package-coupled connection creates relationships between logic channels on node-interconnecting physical links. The term to originate or to terminate a connection, is meant to mean in the circuit-coupled case to connect originating or terminating equipment to a circuit-coupled connection, and in the package-coupled case to create a session between applications in originating and terminating nodes respectively.
The term user is meant to mean in the following a human user or a computer-based application which utilizes communication services. The application may be achieved with hardware, software and combinations thereof. The word "part" is synonymous to the term user.
The term terminal is meant to mean equipment which is connected to a telecommunication network and which makes the telecommunication services of the network available to a user.
The term port either refers to an access port or to a transit port. An access port is a location where a dedicated terminal is connected to a telecommunication network. An access port is associated with a destination address which goes to an end user. In the case of a standard telephone network, the access ports are located in a telephone station. In the case of the ISDN-network and the mobile telephone network, the access ports are found in a terminal. A transit port is a port in a connection between nodes. A transit port is not associated with any particular destination address, and can be used to establish any selected connection with a final destination. The final destination is given by the destination address. A transit port can transfer a call to another node or can receive a call from another node.
The final destination of a call is a terminal which is identified by a destination identity. The terminal can be present in the same node as a transit port or in some other node to which the call shall be further connected.
One fundamental feature of present-day communication services is that when a party, hereinafter called A, wishes to communicate with another party, hereinafter called B, A sends a call to B, whereupon a connection is established between A and B. The call and the establishment of a connection route is a coupled sequence. By this is meant that the information which A uses in the call, namely information relating to the identification of B's access point in the telecommunication network, causes a connection route, or path, to be established between the parties. This connection can either be circuit-coupled or, in the case of noncontinuous transmission methods, a so-called virtual connection, e.g. a package-coupled network, ATM-network (asynchronous transfer mode), etc. Traditionally, a connection is established by establishing a route from an origin to a destination. The connection route through the telecommunication network is controlled by fixed, so-called routing tables which are drawn up when configuring or reconfiguring the network. The routing tables may sometimes permit alternative selections, based on local accessibility information.
The traditional communication network is encumbered with many drawbacks. A first problem concerns handling of the resources of the communication network. Firstly, the communication network is, in itself, a resource which is utilized uneconomically in the traditional method of providing communication services. For example, when party A calls party B, so as to establish a connection through the network from A to B, and party B does not accept the call, the network resources have been used unnecessarily. The same applies when party B is engaged. The case is dependent on the predominant use of present-day networks of channel-associated signalling. This involves establishing a signalling connection, which is then used for speech purposes. With common channel-signalling, which is used primarily in the long-distance network, the signal connection is established with the aid of the data package, or packet, whereas the speech connection, the expensive part of the communication, is not established until B answers. Common channel-signalling is scarcely used in local networks. Secondly, the majority of all established connections do not require party B to act immediately on the information that A will transfer.
In the aforesaid cases, the network resources are either used unnecessarily or are utilized in real time, although it would be possible to utilize the resources at a later time.
Present-day telecommunication networks are constructed on the principle that only a limited number of all potential communication possibilities will be utilized simultaneously by users of the network. The telecommunication network is given an internal architecture so configured that common network resources are able to serve a limited number of users which avail themselves of said resources at one and the same time. Consequently, when a large number of users wish to use the resources simultaneously, the resources are insufficient and a congestion is established. The risk of a congestion being created is reduced by increasing the common resources. However, it is often expensive to increase the common resources. Consequently, an advantage is afforded when the desired communication can be redirected geographically or placed later in time, so that the communication can be effected in a manner which smoothens the traffic and reduces the risk of a congestion, without disadvantage to the users.
Another drawback with the known telecommunication networks is that when party A wishes to communicate with party B, it is necessary for party A to direct the call to the network, since the network must be activated in order to establish the connection with party B. In turn, this requires the network to have knowledge of the access port of party B in the telecommunication network. Furthermore, it is necessary for the telecommunication network to select the connection route between party A and party B. This is achieved with the aid of fixed routing tables. Fixed routing tables, however, are a disadvantage, for instance in the case when a large number of users located within a restricted, local geographic area are called through the telecommunication network at one and the same time, resulting in congestion on certain trunk lines leading to the local area. On such occasions, the node will normally have several unused trunk lines from other geographic areas. The routing tables, however, do not permit these unused trunk lines to be used temporarily for the purpose of relieving the traffic to the local area. By way of example temporary geographic traffic concentrations can be caused by large sporting events of a temporary character, among others.
When seen from the aspect of party B, present-day telecommunication networks are also rigid in structure and slow in redirecting the call to B when B moves from its access port in the telecommunication network. In present-day telephone networks, this problem is solved by service such as "temporary transfer" (diversion) or "redirection". However, if it is necessary for party B to change its access identity permanently, the problem will remain, i.e. that the party who wishes to reach party B must have knowledge of the new access identity. The mobile telephony solves this problem, but at the price of requiring the network to continuously register where B (or B's terminal) can be reached.